He also acknowledged the historical suspicion of federal government among many Americans.

"Through it all, we have never relinquished our skepticism of central authority, nor have we succumbed to the fiction that all society's ills can be cured through government alone," he said.

Yet, in his calls to realize the promise of the Constitution in the present day, Obama made clear his vision of a prominent role for government in society.

"But we have always understood that when times change, so must we; that fidelity to our founding principles requires new responses to new challenges; that preserving our individual freedoms ultimately requires collective action," Obama said.

The address also offered examples of the issues his second administration is likely to take on: gay marriage, gun control, sustainable energy, equal pay for women and immigration reform.

The president also made explicit rebuffs to conservatives, with whom he battled fiercely in his first term.

"The commitments we make to each other through Medicare and Medicaid and Social Security, these things do not sap our initiative, they strengthen us," he said. "They do not make us a nation of takers; they free us to take the risks that make this country great."

In his call to action, Obama appeared to be referring to the partisan bickering that paralyzed Washington at times during his first term -- particularly on discussions about the budget and debt ceiling -- and have eroded public trust in politicians.

"Progress does not compel us to settle centuries-long debates about the role of government for all time, but it does require us to act in our time," Obama said. "For now decisions are upon us and we cannot afford delay. We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate. We must act, knowing that our work will be imperfect."

In their response to Obama's speech, Republicans stressed the nation's budget deficit and the level of federal spending, the Associated Press reported.

"Spending has raged out of control and America's debt has ballooned," House Republican Conference Chair Cathy McMorris Rodgers was quoted saying.